Local network policy document for the Physics Computer (hereafter FysikDatorn).

[Available on-line as http://fy.chalmers.se/Fysikdatorn/Network.html]

Last modified: January 20 1995 by

Andy Polyakov, appro@fy.chalmers.se

Table of Content.

1. What is this document about.
2. Cabling layout.
3. Connections to the network.
4. Network administration.

1. What is this document about. (go back to TOC)

This document specifies rules for ethernet network (re)building, cables allocation and equipment connections in the School of Physics and Engineering Physics (hereafter the School). This specification is subject to changes and corrections. This document describes network administrative tasks performed by Fysikdatorn. The figure below represents network hierarchy and responsibility regions and main types of equipment administered/controlled by FysikDatorn. Hereafter any mention about network concerns corresponding "resposibility region" only.

2. Cabling layout. (go back to TOC)

Network in the School exploits thin-wire Ethernet (hereafter 10Base2) specification. At present time 10Base2 is the only interface provided to the end-users by FysikDatorn.

Per-floor cabling layout for Forskarhuset Fysik depicted on the following figure.

Note cable allocation classes on the figure:

• Class A cables reside in the offices and are put into the wall lead along with telephone wires;
• Class B cables reside in the service corridors and are put on technological shelves;

3. Connections to the network. (go back to TOC)

As carrying out full responsibility for the network reliability FysikDatorn (and only FysikDatorn) performs (or at least supervises) all connections to the common network. It should be mentioned that all equipment should be certified by FysikDatorn before it's connected to the network. FysikDatorn may prohibit to use some kind of equipment on the school network.

The way network equipment gets connected to the network is inherited from cable allocation class:

1. Connections to Class A cables.

   Network equipment is connected by means of 10Base2 extension (drop) cables connected to a wall outlet. Those drop cables including T-connector are property of FysikDatorn and is not subject for leasing or selling. If equipment has a transceiver interface only (hereafter AUI) we strongly recommend to use a microtranciever (directly attachable to the connector) if possible. Twisted-pair ethernet (hereafter 10BaseT) connections are not supported/served by FysikDatorn for Class A cable connections at the present time. Users with legitimate need to often connect/disconnect equipment are treated as they're connected to Class B cable and have multiple computers (see below).

2. Connections to Class B cables.

   Taking into consideration that the Class B cables are serving mostly technological and experimental rooms the eqipment is connected in either of following ways:

   • if there is single computer and it has AUI interface, it gets connected directly to common ethernet backbone with long enough tranceiver cable and 10Base2 transceiver placed on the service corridor wall inside the room;
   • if there is single computer, it has 10Base2 interface only and placed not further than 2 meters from the service corridor wall, it gets connected directly to the common ethernet backbone with 10Base2 extension cables;
   • if there are multiple computers and all of them have 10BaseT interfaces, they get connected through N*10BaseT-to-10Base2 repeater placed on the service corridor wall inside the room;
   • if there are multiple computers and all of them have 10Base2 interfaces (or 10Base2 wiring is prefered), they get connected through two port 10Base2 repeater placed on the service corridor wall inside the room;

   It should be explicitely mentioned that the policy of FysikDatorn is to pay for the network to the wall of labs but not into them, i.e. all extra equipment (repeaters, tranceiver cables) are paid by the end user.

4. Network administration. (go back to TOC)

This chapter describes administrative tasks (configuring, addressing, accounting) performed by FysikDatorn.

At present time FysikDatorn maintains and provides various services based on following networking protocols:

• TCP/IP
• DECnet Phase IV
• AppleTalk Phase II

FysikDatorn considers the TCP/IP networking protocol suite as dominant. FysikDatorn pays most attention to the security, reliability and usage consistency of this protocol family. FysikDatorn may prohibit to use any software/firmware which could break the security, operability or significantly slow down networking performance of computers using TCP/IP protocols family. FysikDatorn (and only FysikDatorn) assigns IP numbers to all computers on the network and configures (or at least supervises and provides aid in configuring) essential parameters required for correct operation of TCP/IP protocol stack. Once assigned IP number is not subject to change (or "lease") by end user, which is considered as coarse violation and may cause administrative penalties.